ah, hmmm, you know, I've not tested the filter with PUT and DELETE.
Love to understand what you are doing here, to understand what you need out of it.

How do you generate the PUTs and DELETEs? I mean I see your .NET code - is this really how you will be generating the requests? And if that is how you are generating them, then why not just generate the requests to the proper URL in the first place?

As you know, URL rewriting is primarily useful for GET requests, particularly for search engine optimization. With PUTs and DELETEs, it sounds like you are building a REST application. So I don't understand why you would want to build the app this
way.

Maybe you could explain what you are thinking, so I have some better insight into what you are trying to do?